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1   /*
2    * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package java.net;
27  
28  import java.io.FileDescriptor;
29  import java.io.FileOutputStream;
30  import java.io.IOException;
31  import java.nio.channels.FileChannel;
32  
33  /**
34   * This stream extends FileOutputStream to implement a
35   * SocketOutputStream. Note that this class should <b>NOT</b> be
36   * public.
37   *
38   * @author      Jonathan Payne
39   * @author      Arthur van Hoff
40   */
41  class SocketOutputStream extends FileOutputStream
42  {
43      static {
44          init();
45      }
46  
47      private AbstractPlainSocketImpl impl = null;
48      private byte temp[] = new byte[1];
49      private Socket socket = null;
50  
51      /**
52       * Creates a new SocketOutputStream. Can only be called
53       * by a Socket. This method needs to hang on to the owner Socket so
54       * that the fd will not be closed.
55       * @param impl the socket output stream inplemented
56       */
57      SocketOutputStream(AbstractPlainSocketImpl impl) throws IOException {
58          super(impl.getFileDescriptor());
59          this.impl = impl;
60          socket = impl.getSocket();
61      }
62  
63      /**
64       * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
65       * object associated with this file output stream. </p>
66       *
67       * The {@code getChannel} method of {@code SocketOutputStream}
68       * returns {@code null} since it is a socket based stream.</p>
69       *
70       * @return  the file channel associated with this file output stream
71       *
72       * @since 1.4
73       * @spec JSR-51
74       */
75      public final FileChannel getChannel() {
76          return null;
77      }
78  
79      /**
80       * Writes to the socket.
81       * @param fd the FileDescriptor
82       * @param b the data to be written
83       * @param off the start offset in the data
84       * @param len the number of bytes that are written
85       * @exception IOException If an I/O error has occurred.
86       */
87      private native void socketWrite0(FileDescriptor fd, byte[] b, int off,
88                                       int len) throws IOException;
89  
90      /**
91       * Writes to the socket with appropriate locking of the
92       * FileDescriptor.
93       * @param b the data to be written
94       * @param off the start offset in the data
95       * @param len the number of bytes that are written
96       * @exception IOException If an I/O error has occurred.
97       */
98      private void socketWrite(byte b[], int off, int len) throws IOException {
99  
100         if (len <= 0 || off < 0 || off + len > b.length) {
101             if (len == 0) {
102                 return;
103             }
104             throw new ArrayIndexOutOfBoundsException();
105         }
106 
107         FileDescriptor fd = impl.acquireFD();
108         try {
109             socketWrite0(fd, b, off, len);
110         } catch (SocketException se) {
111             if (se instanceof sun.net.ConnectionResetException) {
112                 impl.setConnectionResetPending();
113                 se = new SocketException("Connection reset");
114             }
115             if (impl.isClosedOrPending()) {
116                 throw new SocketException("Socket closed");
117             } else {
118                 throw se;
119             }
120         } finally {
121             impl.releaseFD();
122         }
123     }
124 
125     /**
126      * Writes a byte to the socket.
127      * @param b the data to be written
128      * @exception IOException If an I/O error has occurred.
129      */
130     public void write(int b) throws IOException {
131         temp[0] = (byte)b;
132         socketWrite(temp, 0, 1);
133     }
134 
135     /**
136      * Writes the contents of the buffer <i>b</i> to the socket.
137      * @param b the data to be written
138      * @exception SocketException If an I/O error has occurred.
139      */
140     public void write(byte b[]) throws IOException {
141         socketWrite(b, 0, b.length);
142     }
143 
144     /**
145      * Writes <i>length</i> bytes from buffer <i>b</i> starting at
146      * offset <i>len</i>.
147      * @param b the data to be written
148      * @param off the start offset in the data
149      * @param len the number of bytes that are written
150      * @exception SocketException If an I/O error has occurred.
151      */
152     public void write(byte b[], int off, int len) throws IOException {
153         socketWrite(b, off, len);
154     }
155 
156     /**
157      * Closes the stream.
158      */
159     private boolean closing = false;
160     public void close() throws IOException {
161         // Prevent recursion. See BugId 4484411
162         if (closing)
163             return;
164         closing = true;
165         if (socket != null) {
166             if (!socket.isClosed())
167                 socket.close();
168         } else
169             impl.close();
170         closing = false;
171     }
172 
173     /**
174      * Overrides finalize, the fd is closed by the Socket.
175      */
176     protected void finalize() {}
177 
178     /**
179      * Perform class load-time initializations.
180      */
181     private native static void init();
182 
183 }